Transpiration — Paper 3 · IGCSE Sciences - Co-ordinated (Double) 0654

8 Fig. 8.1 is a drawing of a green plant. Fig. 8.1 (a) Add two arrows to Fig. 8.1 to show the direction of movement of water into and out of the plant. [2] (b) State the name of the vessel that carries water through the plant. … [1] (c) Water is needed by the plant for photosynthesis. Name one other requirement for photosynthesis. … [1] (d) Water is lost from the plant by a process called transpiration. State two environmental conditions that will increase the rate of transpiration. 1 … 2 … [2]

6 marks

Mark scheme: 8(a) one arrow pointing into the roots ; one arrow pointing out from the leaf ; 2 8(b) xylem ; 1 8(c) light / carbon dioxide / chlorophyll ; 1 8(d) higher temperature / hot ; increased wind speed / windy ; arid / dry (conditions) ; max 2

This question in 0654/31 May/June 2017

6 Fig. 6.1 is a graph that shows the rate of water loss from a plant during a 24-hour period. The rate of water loss is equivalent to the rate of transpiration. 30 25 20 rate of water loss / grams 15 per hour 10 5 0 00:00 04:00 08:00 12:00 16:00 20:00 24:00 time of day / hour Fig. 6.1 (a) (i) Use Fig. 6.1 to describe how the rate of water loss changes during a 24-hour period. … … … [2] (ii) Suggest reasons why the rate of water loss is lowest at 24:00 hours. … … … [2] (iii) Calculate the difference in rate of water loss between 12:00 and 24:00 hours. … grams per hour [1] (b) Water enters the plant through the root hair cells and is lost by transpiration. (i) Put the letters in the correct order to show the pathway of water through the plant. Two have been done for you. • mesophyll cells A • root cortex cells B • root hair cell C • stomata D • xylem E C E [1] (ii) State one function of root hair cells apart from absorption of water. … [1] (iii) Suggest one use of water absorbed by the plant. … [1]

8 marks

Mark scheme: 6(a)(i) (rate of) water uptake / transpiration increases then decreases ; extra detail e.g. increases until / peaks at, 1200 / 25 g / h ; 2 6(a)(ii) stomata shut ; lower temperature ; no light ; reduced wind speed ; increased humidity ; max 2 6(a)(iii) 22 (grams per hour) ; 1 6(b)(i) CBEAD ; 1 6(b)(ii) absorb mineral ions ; 1 6(b)(iii) photosynthesis ; transport (ions / sugars) ; support / turgor ; growth / part of cytoplasm ; max 1

This question in 0654/33 May/June 2017

4 (a) Use words or phrases from the list to complete the definition of the term transpiration. Each word or phrase may be used once, more than once or not at all. boiling chlorophyll chloroplast evaporation mesophyll respiration root hair stomata Transpiration is defined as the … of water at the surfaces of the … cells followed by loss of water vapour from plant leaves through the … . [3] (b) Two leaves of similar size are removed from the same plant. They are kept at different temperatures and their masses are recorded for six hours. All other variables are kept the same. • Leaf A is kept at 18 °C. • Leaf B is kept at 35 °C. Fig. 4.1 shows a graph of the results. 1.0 0.9 0.8 0.7 leaf A 0.6 mass / g 0.5 0.4 leaf B 0.3 0.2 0.1 0.0 0 1 2 3 4 5 6 time / hours Fig. 4.1 (i) Using values from the graph, calculate the mass lost by leaf B during the six hours. Show your working. … g [2] (ii) Explain why leaf B lost more mass than leaf A. … … … [2] (c) Describe how water moves from the soil to the cells in the leaves. … … … … [3]

10 marks

Mark scheme: 4(a) evaporation ; mesophyll ; stomata ; 3 4(b)(i) 0.9 – 0.35 ; 0.55 ; 2 4(b)(ii) kept at a higher temperature ; increased rate of transpiration / more water (vapour) is lost ; 2 4(c) enters through root hair (cells) ; by diffusion ; transported by xylem ; up the stem ; max 3

This question in 0654/31 Oct/Nov 2018

4 (a) State the term used to describe the loss of water from a leaf by evaporation. … [1] (b) Two similar leaves are removed from the same plant. • Leaf A is kept in an environment of high humidity. • Leaf B is kept in an environment of low humidity. • All other variables are kept the same. The mass of each leaf is measured each hour for six hours. Table 4.1 shows the results. Table 4.1 time / hours mass of leaf A / g mass of leaf B / g 0 0.90 0.90 1 0.90 0.86 2 0.90 0.83 3 0.87 0.80 4 0.87 0.78 5 0.85 0.78 6 0.85 0.75 (i) Calculate the difference in mass between leaf A and leaf B at six hours. … [1] (ii) Explain the difference in mass between leaf A and leaf B at six hours. … … … … [2] (c) Describe how plants obtain water. … … … [2] (d) (i) Draw a circle around two substances transported by xylem in plants. blood carbon dioxide glucose methane mineral ions oxygen urea water [2] (ii) State one other function of xylem apart from transport. … [1]

9 marks

Mark scheme: 4(a) transpiration ; 1 4(b)(i) 0.10 g ; 1 4(b)(ii) leaf A loses less mass – no mark increased humidity ; less transpiration / evaporation ; less water lost ; max 2 4(c) absorbed / uptake through root hair (cells) ; by diffusion ; 2 4(d)(i) water ; mineral ions ; 2 4(d)(ii) support ; 1

This question in 0654/33 Oct/Nov 2018

7 The graph in Fig. 7.1 shows the effect of temperature on the rate of transpiration through a leaf. lower epidermis rate of transpiration upper epidermis temperature Fig. 7.1 (a) Describe the trends shown in Fig. 7.1. … … … … [2] (b) Water vapour is lost through the stomata during transpiration. Suggest a reason for the difference between the rate of transpiration in the upper and lower epidermis. … … [1] (c) Complete the graph in Fig. 7.2 to show the effect of humidity on the rate of transpiration. Include on your graph: • labels for both axes • a sketch of a suitable line. Fig. 7.2 [2] (d) The words in the list are parts of a plant through which water travels. Write the words in the correct order to show the pathway of water through the plant. One has been done for you. mesophyll cells root cortex cells root hair cells stomata xylem … … pathway … of water … stomata [2] [Total: 7]

7 marks

Mark scheme: 7(a) rate of transpiration increases, then levels out with increasing temperature ; rate of transpiration is greater in the lower epidermis than upper epidermis ; 2 7(b) lower epidermis has more stomata (than upper epidermis) ; 1 7(c) y axis labelled rate of transpiration, x axis labelled humidity ; negative correlation ; 2 7(d) root hair cells root cortex cells xylem mesophyll cells root hair cells correct ; rest correct ; 2

This question in 0654/31 May/June 2019

7 (a) Complete the definition of the term transpiration using words or phrases from the list. You may use each word or phrase once, more than once or not at all. condensation chlorophyll diffusion evaporation mesophyll osmosis phloem root hair Transpiration is the loss of water vapour from plant leaves by … of water at the surfaces of the … cells followed by … of water vapour through the stomata. [3] (b) The graph in Fig. 7.1 shows the effect of humidity on the rate of transpiration. rate of transpiration humidity Fig. 7.1 Describe the relationship between humidity and transpiration. … … [1] (c) Complete the graph in Fig. 7.2 to show the effect of temperature on the rate of transpiration. Include on your graph: • labels on both axes • a sketch of a suitable line. [2] Fig. 7.2 (d) Name the vessel in plants that transports water from the roots to the leaves. … [1] [Total: 7]

7 marks

Mark scheme: 7(a) evaporation ; mesophyll ; diffusion ; 3 7(b) as humidity increases the rate of transpiration decreases ; 1 7(c) y axis labelled rate of transpiration, x axis labelled temperature ; initial positive correlation ; 2 7(d) xylem ; 1

This question in 0654/32 May/June 2019

7 (a) Complete the definition of the term transpiration using words or phrases from the list. You may use each word or phrase once, more than once or not at all. condensation chlorophyll diffusion evaporation mesophyll osmosis phloem root hair Transpiration is the loss of water vapour from plant leaves by … of water at the surfaces of the … cells followed by … of water vapour through the stomata. [3] (b) The graph in Fig. 7.1 shows the effect of humidity on the rate of transpiration. rate of transpiration humidity Fig. 7.1 Describe the relationship between humidity and transpiration. … … [1] (c) Complete the graph in Fig. 7.2 to show the effect of temperature on the rate of transpiration. Include on your graph: • labels on both axes • a sketch of a suitable line. [2] Fig. 7.2 (d) Name the vessel in plants that transports water from the roots to the leaves. … [1] [Total: 7]

7 marks

Mark scheme: 7(a) evaporation ; mesophyll ; diffusion ; 3 7(b) as humidity increases the rate of transpiration decreases ; 1 7(c) y axis labelled rate of transpiration, x axis labelled temperature ; initial positive correlation ; 2 7(d) xylem ; 1

This question in 0654/33 May/June 2019

1 (a) Fig. 1.1 is a diagram of a section through the heart and associated blood vessels. X Fig. 1.1 (i) Name the structure labelled X in Fig. 1.1. … [1] (ii) Name the structure shown in Fig. 1.1 that ensures one-way flow of blood. … [1] (iii) Draw an arrow on Fig. 1.1 to show where blood enters the heart from the lungs. [1] (b) Table 1.1 shows some of the functions of the components of blood. Table 1.1 component of blood function antibody production and phagocytosis … promotes blood clotting … transport of dissolved nutrients … transport of oxygen … Complete Table 1.1 by adding the name of the component of blood which has each function. [4] (c) Substances are transported around the body by blood in blood vessels. Substances are also transported around plants in vessels. Name the two vessels that transport substances in plants. 1 … 2 … [2] (d) Water is one of the substances transported through plants and is lost by the process of transpiration. Complete the definition of the term transpiration using words or phrases from the list. Each word or phrase may be used once, more than once or not at all. absorption diffusion epidermis evaporation palisade cells photosynthesis roots stomata Transpiration is defined as the loss of water vapour from plant leaves by … of water at the surfaces of the mesophyll cells followed by … of water vapour through the … . [3] [Total: 12]

12 marks

Mark scheme: 1(a)(i) septum ; 1 1(a)(ii) valve; 1 1(a)(iii) arrow pointing into the heart from the pulmonary vein ; (furthest right blood vessel) 1 1(b) component of blood function white blood cell ; antibody production and phagocytosis platelets ; promotes blood clotting plasma ; transport of dissolved nutrients red blood cell ; transport of oxygen 4 1(c) xylem ; phloem ; 2 1(d) evaporation ; diffusion ; stomata ; 3

This question in 0654/33 Oct/Nov 2019

10 (a) Water is lost from leaves by transpiration. This causes a loss in mass. A student records the mass of leaves from a plant. He places the leaves under a heat lamp. He records the mass of the leaves every 24 hours for 5 days. The results are shown in Table 10.1. Table 10.1 day mass of leaves / g 1 115 2 100 3 85 4 65 5 58 (i) Calculate the total decrease in mass between day 1 and day 5. … g [1] (ii) The investigation is repeated at a lower temperature. The statements show some predictions. Tick (3) one box to show the correct prediction. The decrease in mass will be less than in the first investigation. The decrease in mass will be more than in the first investigation. The mass will increase not decrease. The decrease in mass will be the same as in the first investigation. [1] (b) State the process by which water is lost from the surfaces of the mesophyll cells during transpiration. … [1] (c) State the name of the part of the leaf where water exits the plant. … [1] (d) A plant obtains water from the soil. Describe how water enters the plant and is transported to the mesophyll cells in the leaves. … … … … … [3] (e) One use of water in a plant is for photosynthesis. (i) State one other use of water in a plant. … [1] (ii) State two other requirements of photosynthesis. 1 … 2 … [2] [Total: 10]

10 marks

Mark scheme: 10(a)(i) 57 (g) ; 1 10(a)(ii) The decrease in mass will be less than in the first investigation ticked ; 1 10(b) evaporation ; 1 10(c) stomata ; 1 10(d) any three from water enters root hair cells ; by osmosis ; ref to root cortex cells ; transferred to leaves by xylem ; Max 3 marks 3 Question Answer Marks 10(e)(i) support / as a solvent / AVP ; 1 10(e)(ii) any two from: light ; warm / suitable, temperature ; carbon dioxide ; chlorophyll ; Max 2 marks 2

This question in 0654/31 May/June 2022

7 (a) A student investigates the effect of temperature on the rate of transpiration. Fig. 7.1 shows the apparatus used. plant shoot capillary tube water ruler air bubble Fig. 7.1 The student measures the distance the air bubble moves in 22 minutes. The distance the air bubble moves is used to calculate the rate of transpiration. The experiment is repeated at three different temperatures. Table 7.1 shows the results. Table 7.1 distance the air bubble temperature moves in 22 minutes / °C / mm 4 3 10 7 25 20 (i) Calculate the rate of transpiration at 10 °C. Give your answer to 1 significant figure. … mm / min [2] (ii) State one other factor that affects the rate of transpiration. … [1] (iii) Define the term transpiration. … … … … … [3] (b) Fig. 7.2 shows the initial pathway of water through a plant. soil particle soil water xylem vessel Y X Fig. 7.2 (i) State the names of the cells labelled X and Y in Fig. 7.2. X … Y … [2] (ii) State the name of the process that causes absorption of water into the plant cells. … [1] [Total: 9]

9 marks

Mark scheme: 7(a)(i) (7 / 22=) 0.318 ; 2 0.3 (mm / min) ; 7(a)(ii) humidity / AVP ; 1 7(a)(iii) any three from: 3 water evaporates from (surfaces of) mesophyll cells ; lost as water vapour (from plant leaves); through the stomata ; by diffusion ; 7(b)(i) X – root hair (cell) ; 2 Y – root cortex (cell) ; 7(b)(ii) osmosis ; 1

This question in 0654/32 Feb/March 2023

10 (a) Fig. 10.1 is a diagram of the gas exchange system in humans. A B C Fig. 10.1 State the names of the parts labelled A, B and C in Fig. 10.1. A … B … C … [3] (b) Describe three ways the composition of expired air is different from inspired air. 1 … … 2 … … 3 … … [3] (c) Gases move across the gas exchange surface by diffusion. Place ticks (✓) next to all the statements that correctly describe diffusion. Diffusion is due to the random movement of particles. Diffusion is the movement of only water molecules. Diffusion occurs across a cell membrane. Diffusion requires energy from aerobic respiration. Diffusion occurs against a concentration gradient. [2] (d) Gas exchange also occurs in plants. (i) State the name of the part of the leaf where water vapour exits. … [1] (ii) State the term used to describe when water evaporates and then diffuses out of a leaf. … [1] (iii) State two factors that increase the rate of water loss from a leaf. 1 … 2 … [2] [Total: 12]

12 marks

Mark scheme: 10(a) A – trachea ; 3 B – bronchus ; C – alveoli ; 10(b) (expired air) 3 contains more carbon dioxide ; contains less oxygen ; contains more water vapour ; 10(c) 2 Diffusion is due to the random movement of particles.  Diffusion is the movement of only water molecules. Diffusion occurs across a cell membrane.  Diffusion requires energy from aerobic respiration. Diffusion occurs against a concentration gradient. ;; all correct = 2 marks three ticks and two correct = 1 mark otherwise = 0 marks 10(d)(i) stoma / stomata ; 1 10(d)(ii) transpiration ; 1 10(d)(iii) any two from: 2 increase in temperature ; decrease in humidity ; AVP ;

This question in 0654/32 Oct/Nov 2023

10 (a) Fig. 10.1 is a diagram of a cross-section through a leaf. X Y Fig. 10.1 (i) State the name of the part labelled X and the cell labelled Y in Fig. 10.1. part X … cell Y … [2] (ii) Draw one arrow on Fig. 10.1 to show the pathway of water vapour during transpiration. [1] (b) Fig. 10.2 is an incomplete sketch graph. Complete Fig. 10.2 to show the effect of humidity on the rate of transpiration by: • including axis labels • drawing a line to show the trend. Fig. 10.2 [2] (c) State the name of the type of plant cell that absorbs water from the soil. … [1] (d) State the name of the plant tissue that transports water from the roots to the leaves. … [1] (e) Suggest one reason why not all the water absorbed is lost through transpiration. … … [1] (f) Blood has several functions including transport in humans. (i) State one function of white blood cells. … [1] (ii) State two other main components of blood. 1 … 2 … [2] [Total: 11]

11 marks

Mark scheme: 10(a)(i) X – (upper) epidermis ; 2 Y – spongy mesophyll ; 10(a)(ii) arrow drawn from leaf going out of stoma ; 1 10(b) axis labels ; 2 negative correlation ; 10(c) root hair (cell) ; 1 10(d) xylem ; 1 10(e) some used in, photosynthesis / support ; 1 10(f)(i) phagocytosis / production of antibodies ; 1 10(f)(ii) any two from: 2 red blood cells ; plasma ; platelets ;

This question in 0654/33 Oct/Nov 2023

1 Fig. 1.1 shows a part of a cross-section of a plant stem. Fig. 1.1 (a) On Fig. 1.1, draw a label line and the letter Y to identify the part of the stem that transports sucrose. [1] (b) Sucrose is a type of carbohydrate. Complete the sentences about carbohydrates in plants. Plants make carbohydrates using the process of … . This process requires water and … in the presence of … energy and chlorophyll. [3] (c) Water travels through the plant from the roots to the leaves. Complete the flow chart to show the pathway of water through a plant. roots root hair cells root … cells xylem leaves … cells [2] (d) Water evaporates inside the leaves to form water vapour. Water vapour is then lost from the leaves. (i) State the name of the process that describes the loss of water vapour from leaves. … [1] (ii) Circle the part where water vapour exits the leaf. cuticle palisade stomata vascular bundles [1] [Total: 8]

8 marks

Mark scheme: Question Answer Marks 1(a) correct line drawn and labelled Y ; 1 1(b) photosynthesis ; 3 carbon dioxide / CO2 ; light ; 1(c) cortex ; 2 mesophyll ; 1(d)(i) transpiration ; 1 1(d)(ii) stomata ; 1

This question in 0654/31 May/June 2025